Exciton fission and annihilation in crystalline tetracene

1977 ◽  
Vol 30 (11) ◽  
pp. 2353 ◽  
Author(s):  
GR Fleming ◽  
DP Millar ◽  
GC Morris ◽  
JM Morris ◽  
GW Robinson
Keyword(s):  
Room Temperature ◽  
Streak Camera ◽  
Annihilation Rate ◽  
Time Resolved Fluorescence ◽  
Time Resolved ◽  
Singlet Exciton ◽  
Exciton Lifetime ◽  
Upper Limit ◽  
Exciton Annihilation ◽  
Hopping Model

The time-resolved fluorescence of tetracene crystals excited by a single 7-ps pulse of 530-nm light has been measured with a streak camera/OMA system. The singlet exciton lifetime was found to be 300�30 ps at 293 K. Singlet-singlet exciton annihilation was observed, and the rate constant found to be 5 x 10-9 cm3 s-1. In order to fit the observed decay curves, an upper limit of c. 1 x 10-9 cm3 s-1 must be set on the singlet-triplet exciton annihilation rate. The measured singlet-singlet exciton annihilation rate is consistent with a hopping model for singlet exciton motion at room temperature.

scholarly journals An Improved Version of Photon-Counting Streak Camera and Its Application to Time-Resolved Fluorescence Spectrophotometer.

1994 ◽  
Vol 43 (3) ◽  
pp. 164-170
Author(s):  
Seiji AKIMOTO ◽  
Yoshinobu NISHIMURA ◽  
Iwao YAMAZAKI ◽  
Motoyuki WATANABE ◽  
Musubu KOISHI
Keyword(s):  
Streak Camera ◽  
Photon Counting ◽  
Time Resolved Fluorescence ◽  
Time Resolved

scholarly journals Time-Resolved Fluorescence Spectrophotometer by Means of Photon-Counting Streak Camera.

1991 ◽  
Vol 40 (3) ◽  
pp. 155-162
Author(s):  
Yoshinobu NISHIMURA ◽  
Tomoko YAMAZAKI ◽  
Iwao YAMAZAKI ◽  
Motoyuki WATANABE ◽  
Musubu KOISHI
Keyword(s):  
Streak Camera ◽  
Photon Counting ◽  
Time Resolved Fluorescence ◽  
Time Resolved

scholarly journals Monitoring ovarian function by the simultaneous time-resolved fluorescence immunoassay of two urinary steroid metabolites

1998 ◽  
Vol 44 (7) ◽  
pp. 1520-1528 ◽  
Author(s):  
Geoff Barnard ◽  
Fortune Kohen
Keyword(s):  
Room Temperature ◽  
Ovarian Function ◽  
Early Morning ◽  
Fluorescence Immunoassay ◽  
Time Resolved Fluorescence ◽  
Time Resolved ◽  
Menstrual Cycles ◽  
Lanthanide Chelates ◽  
Coated Plate ◽  
Urinary Steroid

Abstract We report the development of a novel time-resolved fluorescence immunoassay utilizing two different assay strategies for the simultaneous measurement of estrone-3-glucuronide (EG) and pregnanediol-3α-glucuronide (PG) in samples of early morning urine (EMU). The method for the measurement of EG involves the use of a labeled anti-idiotype as a surrogate antigen, whereas the other method (for the measurement of PG) is a regular competitive immunoassay using a labeled antigen. In addition, the procedure uses different lanthanide chelates as labels to monitor ovarian function in women. After washing the streptavidin-coated plate, we added 10 μL of undiluted urine or mixed standard to the coated wells, followed by the addition of 100 μL of assay buffer containing the labeled reactants (i.e., europium-labeled PG and samarium-labeled anti-idiotype recognizing the binding site of the antibody to EG). Subsequently, we added 100 μL of assay buffer containing the two biotinylated specific monoclonal anti-steroid glucuronide antibodies. After incubation for 1 h on a shaker at room temperature, we washed the plate and added 200 μL of enhancement solution to each well. We measured europium and samarium fluorescence, using a gated plate fluorometer with appropriate emission filters. The method demonstrates appropriate sensitivity and precision (all CVs, 5–8%) across the relevant working ranges for each analyte. The technique has been applied to serial EMUs collected from women with normal and stimulated menstrual cycles.

scholarly journals Intramolecular Photoinduced Electron Transfer in Zwitterionic Quinolinium Dyes – Experimental and Theoretical Studies

2002 ◽  
Vol 216 (3) ◽  
Author(s):  
T. Engel ◽  
G. Käb ◽  
H. Lanig
Keyword(s):  
Electron Transfer ◽  
Photoinduced Electron Transfer ◽  
Room Temperature ◽  
Intramolecular Interaction ◽  
Time Resolved Fluorescence ◽  
Time Resolved ◽  
Reaction Field ◽  
Experimental And Theoretical Studies ◽  
Dynamic Fluorescence ◽  
Semiempirical Quantum Chemical Calculations

Quinolinium cations and quinolinium betaines were investigated in the representative solvents water and acetonitrile at room temperature using stationary and time-resolved fluorescence spectroscopy (Experimental results reveal that sulfoalkyl- and carboxyalkyl-quinolinium compounds display a strikingly different behavior in the two solvents. Furthermore, the fluorescence lifetime depends on the length of the spacer for the sulfoalkyl compounds in acetonitrile and the carboxyalkyl compounds in water, respectively. This suggests an intramolecular interaction of the anionic headgroups with the quinolinium system in the excited state. To support this idea, different positions at the chromophore are substituted by a methylgroup in order to perturb the proposed interaction.With the intention to understand the dynamics of the postulated photoinduced electron transfer from the anionic group onto the excited quinolinium chromophore, semiempirical quantum chemical calculations were performed on the species using the PM3 hamiltonian including solvent effects by a self consistent reaction field (SCRF).We show that the Marcus theory of electron transfer may serve as a theoretical basis for a natural interpretation of the dynamic fluorescence quenching behavior.

Phosphorescent labeling reagents of platinum(II) and palladium(II) coproporphyrin-II: Preparation and performance characteristics

2002 ◽  
Vol 06 (08) ◽  
pp. 533-543 ◽  
Author(s):  
Mirva M. Koskelin ◽  
Aleksi E. Soini ◽  
Niko J. Meltola ◽  
Gelii V. Ponomarev
Keyword(s):  
Room Temperature ◽  
Time Resolved Fluorescence ◽  
Reactive Group ◽  
Time Resolved ◽  
Emission Efficiency ◽  
Alkaline Conditions ◽  
Phosphorescence At Room Temperature ◽  
And Performance ◽  
Derivatives Of ◽  
Coproporphyrin I

Synthesis of monofunctional derivatives of platinum(II) and palladium(II) coproporphyrin-II with the isothiocyanato reactive group is presented. The compounds exhibit strong phosphorescence at room temperature in deoxygenated aqueous solutions and they enable facile covalent labeling of proteins and other biomolecules under slightly alkaline conditions. The performance of the compounds as phosphorescent labeling reagents is studied and the results are considered in relation to the results for the respective labeling reagent of coproporphyrin-I isomer. The results show that the derivatives of coproporphyrin-II exhibit similar reactivity and emission efficiency to that of the derivatives of coproporphyrin-I isomers. Thus, the coproporphyrin-II derivatives serve as alternative labels to coproporphyrin-I in the design of sensitive bioassays based on phosphorescence and time-resolved fluorescence detection.

scholarly journals Time-Resolved Fluorescence Spectrophotometer Using a Traveling Wave Plate Type Streak Camera.

1996 ◽  
Vol 24 (5) ◽  
pp. 609-614
Author(s):  
Seiji AKIMOTO ◽  
Akira TAKAHASHI ◽  
Katsuyuki KINOSHITA ◽  
Motoyuki WATANABE ◽  
Musubu KOISHI ◽  
...  
Keyword(s):  
Traveling Wave ◽  
Streak Camera ◽  
Time Resolved Fluorescence ◽  
Time Resolved ◽  
Wave Plate ◽  
Plate Type

scholarly journals Analysis of Fluorescence Quenching of BPBD by Aniline in Toluene

2013 ◽  
Vol 12 (1) ◽  
pp. 87-98
Author(s):  
J Thipperudrappa ◽  
S M Hanagodimath
Keyword(s):  
Steady State ◽  
Fluorescence Quenching ◽  
Room Temperature ◽  
Static Quenching ◽  
Approximation Model ◽  
Positive Deviation ◽  
Time Resolved Fluorescence ◽  
Time Resolved ◽  
Steady State Method ◽  
Volmer Plot

Fluorescence quenching of 2-(4'-t-Butylphenyl)-5-(4"-biphenylyl)-1,3,4-oxadiazole (BPBD) by aniline in toluene has been carried out at room temperature by steady state and time resolved fluorescence spectroscopy. The Stern-Volmer plot by steady state method has been found to be non-linear showing a positive deviation, whereas by time-resolved method it is linear. In order to interpret these results we have used the ground state complex and sphere of action static quenching models. Using these models various rate parameters have been determined. Based on these models, with finite sink approximation model, we conclude that positive deviation Stern-Volmer plot is due to the simultaneous presence of dynamic and static quenching processes.

Sign in / Sign up

Export Citation Format

Share Document